hintonda added a comment. Just ran asan on linux and we have a heap-use-after-free in the std::string ctor.
Here's a partial stack dump: 4980==ERROR: AddressSanitizer: heap-use-after-free on address 0x604000024328 at pc 0x00000057ad32 bp 0x7ffd240a7f50 sp 0x7ffd240a7700 ------------------------------------------------------------------------------------------------------------------------------------- READ of size 8 at 0x604000024328 thread T0 #0 0x57ad31 in __interceptor_memcpy.part.36 /home/d80049854/projects/clang/4.0.0/llvm/projects/compiler-rt/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:655 #1 0x6c5960 in char* std::string::_S_construct<char const*>(char const*, char const*, std::allocator<char> const&, std::forward_iterator_tag) /usr/lib/gcc/x86_64-linux-gnu/6.2.0/../../../../include/c+ +/6.2.0/bits/basic_string.tcc:580:6 #2 0x7fe7bd7bc98a in std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(char const*, unsigned long, std::allocator<char> const&) (/usr/lib/x86_64-linux-gnu/libstdc++. so.6+0xc598a) #3 0x67b89f in llvm::StringRef::str() const /home/d80049854/projects/clang/llvm/include/llvm/ADT/StringRef.h:230:14 #4 0x67b3dd in llvm::StringRef::operator std::string() const /home/d80049854/projects/clang/llvm/include/llvm/ADT/StringRef.h:257:14 #5 0xd679d2 in clang::FixItHint::CreateReplacement(clang::CharSourceRange, llvm::StringRef) /home/d80049854/projects/clang/llvm/tools/clang/include/clang/Basic/Diagnostic.h:131:25 #6 0x1213006 in clang::tidy::modernize::UseNoexceptCheck::check(clang::ast_matchers::MatchFinder::MatchResult const&) /home/d80049854/projects/clang/llvm/tools/clang/tools/extra/clang-tidy/modernize/U $ ../../4.0.0/build/Release/bin/clang -v clang version 4.0.0 (tags/RELEASE_400/final) Target: x86_64-unknown-linux-gnu Thread model: posix InstalledDir: /home/d80049854/projects/clang/build/Debug/../../4.0.0/build/Release/bin Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.6 Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.6.4 Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8 Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8.4 Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.9 Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.9.3 Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5 Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.4.1 Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6 Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6.2.0 Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6.2.0 Candidate multilib: .;@m64 Selected multilib: .;@m64 stdlibc++ from gcc 6.2: $ g++-6 -v Using built-in specs. COLLECT_GCC=g++-6 COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/6/lto-wrapper Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Ubuntu 6.2.0-3ubuntu11~14.04' --with-bugurl=file:///usr/share/doc/gcc-6/README.Bugs --enable-languages=c,ada,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-6 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=gcc4-compatible --disable-libstdcxx-dual-abi --enable-gnu-unique-object --disable-vtable-verify --enable-libmpx --enable-plugin --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-6-amd64/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-6-amd64 --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-6-amd64 --with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --enable-objc-gc --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu Thread model: posix gcc version 6.2.0 20160901 (Ubuntu 6.2.0-3ubuntu11~14.04) $ ldd bin/clang-tidy linux-vdso.so.1 => (0x00007ffde1996000) libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f6104f2a000) librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f6104d22000) libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f6104b1e000) libtinfo.so.5 => /lib/x86_64-linux-gnu/libtinfo.so.5 (0x00007f61048f5000) libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f61045ef000) libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f61042dd000) libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f61040c6000) libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f6103d01000) /lib64/ld-linux-x86-64.so.2 (0x00007f6105148000) https://reviews.llvm.org/D20693 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
